There are known devices for preventing insertion into loading apparatus of an incorrectly oriented cartridge, but many of such devices are not operative whether a cartridge is inserted longitudinally (front-edge first) or laterally (side-edge first). Also, they typically require the cartridge to be inserted to nearly or over half the full insertion distance in order to be operative. For example, Japanese documents 50-34516 and 47-36088 show devices for a Compact Cassette which detect the increased thickness of the cassette on the edge of one of its faces. Such detection does not occur until the cassette has been inserted to almost 80% of the insertion distance. The drawback of such devices is that the user, having inserted the cartridge as far as it will go, is convinced that it is positioned correctly and, therefore, tries to continue the insertion movement by exerting greater force, with the risk of damaging the cartridge, the tray receiving the cartridge, and/or the loading apparatus.
U.S. Pat. No. 5,022,023 proposes a disc reader device provided with mechanical sensors determining whether the disc inserted by the user has a small or large diameter, and releasing or not releasing guide pieces in accordance with this determination. If applied to cartridges, such a device could be used for positioning cartridges of different sizes, but would not be capable of detecting whether the cartridges were correctly oriented.